Here's why:

* Sunlight contains all colors of the rainbow: The sun emits light across the entire visible spectrum, including all the colors we see in a rainbow.

* Our atmosphere scatters blue light: The blue wavelengths of light are scattered more readily by the Earth's atmosphere, making the sky appear blue. This is why the sun appears yellow or orange at sunrise and sunset, when the light has to travel through more of the atmosphere.

* White is the combination of all colors: When all colors of the rainbow are mixed together, they create white light.

So, while we perceive the sun as yellow or orange most of the time, its true color is white!